Microencapsulation in the Food Industry

A Practical Implementation Guide

Robert Sobel, Anilkumar G. Gaonkar, Niraj Vasisht, Atul R. Khare

• Publisher: Academic Press
• Year: 2014
• eBook ISBN: 9780124047358
• Topic: Tecnologia e ingegneria
• Subtopic: Scienze dell'alimentazione

Microencapsulation is being used to deliver everything from improved nutrition to unique consumer sensory experiences. It's rapidly becoming one of the most important opportunities for expanding brand potential. Microencapsulation in the Food Industry: A Practical Implementation Guide is written for those who see the potential benefit of using microencapsulation but need practical insight into using the technology. With coverage of the process technologies, materials, testing, regulatory and even economic insights, this book presents the key considerations for putting microencapsulation to work. Application examples as well as online access to published and issued patents provide information on freedom to operate, building an intellectual property portfolio, and leveraging ability into potential in licensing patents to create produce pipeline.This book bridges the gap between fundamental research and application by combining the knowledge of new and novel processing techniques, materials and selection, regulatory concerns, testing and evaluation of materials, and application-specific uses of microencapsulation. - Practical applications based on the authors' more than 50 years combined industry experience - Focuses on application, rather than theory - Includes the latest in processes and methodologies - Provides multiple "starting point" options to jump-start encapsulation use

Part I

Introduction

Outline

Chapter 1 Introduction to Microencapsulation and Controlled Delivery in Foods

Chapter 1

Introduction to Microencapsulation and Controlled Delivery in Foods

Robert Sobel^1,2, Ronald Versic² and Anilkumar G. Gaonkar³, ¹FONA International, Geneva, Illinois, USA, ²Ronald T. Dodge Company, Dayton, Ohio, USA, ³Mondelēz International, Glenview, Illinois, USA

Microencapsulation, simply stated, is a means of packaging, separating, and storing materials in microscopic capsules for later release under controlled conditions. The versatile technologies that have resulted from the evolution of this science have been widely used in the food industry, both to improve product performance and provide better controlled delivery of ingredients. The morphology of microencapsulation falls into two categories: microcapsules and microspheres. The history of both types coincides with the development of atomization technologies and chemical processing techniques; and microencapsulation applications in the food industry are common to both categories. Microencapsulation techniques and types used in the food industry are carefully regulated, and must meet various governmental and industry regulatory authorities. Selection and development of microencapsulated food ingredients for controlled delivery require a careful balance of physical and chemical properties and processing of ingredients, available techniques, and regulatory guidelines.

Keywords

microencapsulation; microcapsules; microparticles; release triggers; controlled delivery; controlled release; food ingredients

1.1 Introduction

This introductory chapter provides the background, including the necessary theory and impetus, for the art and science of microencapsulation techniques found within the food industry. The spirit of this communication is to provide a background of encapsulation techniques and procedures that are contemporary to the field of encapsulation technology, thus giving the reader a clearer understanding of the science and an improved ability to apply this technology in their environment.

This chapter is divided into nine key areas consisting of: (1) microencapsulation defined, (2) reasons for microencapsulation, (3) types of microcapsules, (4) a historical account of encapsulation, (5) materials used for encapsulation purposes and their regulatory aspects, (6) microencapsulation techniques used within the food industry and examples thereof, (7) trends in microencapsulation, (8) challenges in microencapsulation of food ingredients, and (9) the future of microencapsulation of food ingredients. The culmination of these nine areas becomes the foundation of material presented herein.

This introductory chapter is the first of seven parts of this book. Part 2 describes concepts related to factors, mechanisms, mass, and heat transfer. Different process technologies using microencapsulation of food ingredients are the subject matter of Part 3. Part 4 deals with various materials (matrix, coating, excipient, etc.) used for microencapsulation of food ingredients. Testing and quality control are the subjects for Part 5. Regulatory, quality, scale-up, packaging, and economics are addressed in Part 6. Finally, applications of microencapsulation technologies are described in Part 7.

1.2 Microencapsulation defined

Microencapsulation (as it applies to the food industry) is the process whereby various food ingredients can be stored within a microscopic size shell or coating for protection and/or later release. More specifically, microencapsulation is the process of enclosing small particles, a liquid, or a gas within a layer of coating or within a matrix. Traditionally, microencapsulation does not utilize capsules greater than 3 mm in length. Encapsulations that fall within the range of 100 nm to 1000 nm are classified as microencapsulations. Components that are between 1 nm and 100 nm are classified as nanocapsules or nanoencapsulations (Thies, 1996).

The common nomenclature used to define the various parts of the encapsulate includes terminology for the shell as well as the ingredient to be encapsulated. The ingredient that is to be encapsulated is usually called an active, core, payload, internal phase, encapsulate, or fill. The material that envelopes the active is commonly called shell, wall, coating, external phase, support phase, or membrane. The shell material is usually insoluble and nonreactive with the core. It accounts for 1 to 80% of the microcapsules by weight. The microencapsulant’s shell can be made of sugars, gums, proteins, natural and modified polysaccharides, lipids, waxes, and synthetic polymers (Gibbs et al., 1999).

1.3 Reasons for microencapsulation

Microencapsulation—considered both an art and a science—is a versatile technology used in a variety of industries. Examples include the pharmaceutical, chemical, food, and agricultural industries. One reason for using microencapsulation technologies is ingredient protection, that is, to avoid degradation resulting from exposure to environmental factors such as water, oxygen, heat, and light. Traditionally, this is done to improve the shelf-life of the active material. In some cases, encapsulation can be used to mask undesirable taste, odor, and color, thus preventing interference with product performance. Ease of handling is another reason for microencapsulating, as it can be used as a simple method for converting a liquid food ingredient into a solid (free-flowing powder). Microencapsulation can be used to prevent reactions and undesirable interactions between active food ingredients and those between actives and food components. Considering the ease of handling, microencapsulation also provides the opportunity to reduce the flammability and volatility of various food ingredients. Finally, microencapsulation can be used to control the delivery of a food ingredient. This is known as controlled release or controlled delivery.

Controlled release of food ingredients by microencapsulation can be achieved through understanding the mechanism by which the food ingredient is to be released. Various release mechanisms, also known as release triggers or signaled release, include temperature (thermal: heat, cold); moisture or solvent release via dissolution; shear or pressure release (mechanical, chewing (mastication)); pH; and enzymatic release. Triggered release is usually fine-tuned to a specific target release point. This also includes delayed release, or sustained release, over time. Targeted release seeks delivery of the food ingredient at a specific processing or storage stage, the specific consumption stage of the consumer good, or a specific location within the body (i.e., gastrointestinal tract).

The microencapsulation system must be designed with the release mechanism (trigger) in mind. As indicated earlier, an active food ingredient (payload) can be delivered at different stages of the processing, storage, and consumption cycle. The release trigger used will largely depend on the type of the food/beverage product and the location at which the payload needs to be released. Water (moisture) is used as the release trigger for releasing an active during rehydration and dissolution of a food powder when the water is added. The same is applicable when saliva dissolves a ready-to-eat food product during mastication. Water-soluble or -dispersible matrix/coatings (e.g., carbohydrates and/or proteins) are employed when the active needs to be released with water as a release trigger. Heat is used as the release trigger (thermal trigger) to release an active after warming, cooking, baking, roasting, steaming, or microwaving a food product. Examples include an addition of hot water to the food powder used to prepare hot drinks (coffee, tea, cocoa drink, chocolate drink, etc.) and soups. When heat is the preferred release trigger, lipids, fats, and waxes are used as matrix/shell materials. Mechanical shear (mastication) is used as the release trigger during chewing of a ready-to-eat (RTE) food. Enzymes and pH are used as release triggers when an active has to be delivered in a specific part of the gastrointestinal tract (i.e., mouth, stomach, small intestine, or the colon). The matrix/coating made up of a starch (sensitive to amylase in the mouth) is ideal for release in the mouth. When the matrix/coating is made up of protein, it would disintegrate in the presence of proteases in the stomach. Enteric food polymers such as zein, shellac, and denatured proteins are stable (insoluble) in the stomach (high acid environment; low pH) and soluble (disintegrates) at the pH environment existing in the small intestine. Hence, enteric polymers are employed for stabilizing the active until it exits the stomach and releases in the small intestine.

It is clear from these examples and applications of encapsulation that the food processing and consumption cycle is critical to the development of the trigger release mechanism used.

At the start of the cycle, consideration must be given to the ingredients and how they will interact with the processing step: this applies to both the creation of the microencapsulation system and the development and production of the finished food product. The processing step in the manufacture of a food product may involve shear, temperature (heat or cold), pressure, aeration, and addition of moisture. How these parameters affect the integrity of the microcapsules must be taken into account while developing the system itself. Once the food product is processed, its storage and handling must also be considered: this is done to ensure that the previously encapsulated food ingredients will be able to withstand the shelf-life and storage condition of the material. The final step in the cycle is the preparation of the food by the consumer. The microencapsulation must be able to perform and deliver the food ingredient at the appropriate time, that is, during cooking, at hydration, or when the finished product is consumed (i.e., mastication).

Information on microencapsulation of aroma, acidulant, bacteria, base/buffe...

Table of contents

• Cover image
• Title page
• Table of Contents
• Dedication
• Copyright
• Foreword
• Preface
• About the Editors
• List of Contributors
• Part I: Introduction
• Part II: Concept of Microencapsulation
• Part III: Process Technologies in Microencapsulation
• Part IV: Materials Used in Microencapsulation
• Part V: Testing and Quality Control
• Part VI: Regulatory, Quality, Process Scale-Up, Packaging, and Economics
• Part VII: Microencapsulation Applications
• Index